This invention relates generally to a process for producing charcoal, and in particular to a technique wherein cellulosic stock is converted, without combustion, into charcoal by means of a catalytic agent.
Charcoal is a substance composed almost entirely of carbon, hydrogen, oxygen, this product being usually obtained by burning organic material in the absence of air by a destructive distillation technique. Because of its physical and chemical properties, charcoal yields a greater amount of heat in proportion to its volume than is obtainable from a corresponding quantity of wood. Moreover, as a fuel, it has the further advantage of being virtually smokeless.
Charcoal has a wide range of applications; for not only is it a valuable fuel, but it has metallurgical, chemical and various other practical uses. For economic reasons, the use of charcoal in metallurgy has given way to coke, but it remains an important material for the chemical industry. In its activated form it is useful as an adsorptive agent for the purification of gas and liquids.
In my above-identified copending application, cellulosic stock from any available source is subjected to hydrolysis by a liquid anhydrous chloride agent and converted thereby into glucose and other reducing substances. The glucose is then fermented to produce ethanol or ethyl alcohol, a valuable fuel as well as a solvent. In the present invention, the same agent or an agent having analogous chemical characteristics is used to effect conversion of cellulose into charcoal which is usable as a fuel or for any other known purpose.
Because billions of tons of carbon are fixed every year on the land area of the earth by photosynthesis, out of which about half appears in the form of cellulose, the ability to convert cellulose into almost pure carbon (i.e. charcoal) at low cost, affords a potential source of fuel of extraordinary magnitude. The fact that petroleum-derived hydrocarbon fuels are becoming increasingly scarce and much more expensive lends particular significance to this alternative source of fuel. Moreover, this source, which is derived from wood and other organic matter, is renewable and therefore effectively inexhaustible.